You'll need to add a whole slew of hosts for intercom if you've got CSP in place (which you should).
Heres what you'll need to add (updated from intercom support request):
connect-src:
api.intercom.io
api-iam.intercom.io
api-ping.intercom.io
nexus-websocket-a.intercom.io
nexus-websocket-b.intercom.io
nexus-long-poller-a.intercom.io
nexus-long-poller-b.intercom.io
wss://nexus-websocket-a.intercom.io
wss://nexus-websocket-b.intercom.io
uploads.intercomcdn.com
font-src:
js.intercomcdn.com
frame-src:
share.intercom.io
www.youtube.com
player.vimeo.com
fast.wistia.net
img-src:
js.intercomcdn.com
static.intercomassets.com
uploads.intercomcdn.com
data:
script-src:
app.intercom.io
widget.intercom.io
js.intercomcdn.com
style-src:
'unsafe-inline'